Drum extender apparatus for melting and dispensing hot melts

Abstract

An improved melting and dispensing apparatus is provided. The apparatus includes an annular drum extender flange which permits the apparatus to be utilized with drums of hot melt or moisture-curable hot melt materials which are completely filled.

We claim: 
     
       1. An apparatus for melting and dispensing a hot melt type adhesive which comprises: a cylindrical container for holding hot melt type adhesive to be melted and dispensed in a molten liquid state, said container having one closed end and one open end,   means for supporting said container in an upright position with said open end facing upward,   a cylindrical platen having an `O` ring seal on its side and having an orifice through which molten adhesive is pumped, said platen being positioned to fit into the open end of said container and sized so that the `O` ring seal slideably engages the inside wall of said container,   means for heating said platen to melt said adhesive,   pumping means for pumping molten adhesive through said orifice,   means for pressing said heated platen in a downward motion into said adhesive and withdrawing said platen when the container has been emptied;   an annular drum extender flange positioned upon the open end of said container, said flange having an inside diameter about the same as that of said container and having a height sufficient to engage said `O` ring seal of said heated platen, and lip means to cooperate with the open end of said container, and   clamping means for securing said annular flange to said container;   whereby the apparatus is capable of accommodating containers completely filled, without headspace.   
     
     
       2. The apparatus of claim 1 wherein said supporting means includes a flat base. 
     
     
       3. The apparatus of claim 1 wherein said heating means includes electrical resistance wires embedded in said platen. 
     
     
       4. The apparatus of claim 1 wherein said pressing means includes pneumatic cylinders. 
     
     
       5. The apparatus of claim 1 wherein said lip means includes a U-shaped lip. 
     
     
       6. The apparatus of claim 1 wherein said clamping means includes a retaining ring. 
     
     
       7. The apparatus of claim 1 wherein said clamping means is attached to the flange and includes a handle connected to a gripper by an adjustable nut or screw wherein said gripper is adapted to engage the open end of said drum. 
     
     
       8. The apparatus of claim 1 wherein said annular drum extender flange is coated with a non-stick coating on the inside wall and on the inside of the lip means. 
     
     
       9. The apparatus off claim 8 wherein said non-stick coating comprises a tetrafluoroethylene fluorocarbon polymer or a fluorinated ethylene-proplyene resin. 
     
     
       10. The apparatus of claim 1 wherein said cylindrical container comprises an open head drum. 
     
     
       11. The apparatus of claim 1 wherein said cylindrical container is filled with a hot melt material to be dispensed. 
     
     
       12. The apparatus of claim 11 wherein said container is filled with a moisture-curable material to be dispensed. 
     
     
       13. The apparatus of claim 12 wherein said moisture-curable material comprises a prepolymer derived from diphenyl methane diisocyanate and a polyester derived from an aliphatic dicarboxylic acid and an aliphatic diol. 
     
     
       14. The apparatus of claim 1 wherein said hot melt adhesive comprises a prepolymer derived from an aromatic of aliphatic isocyanate and a polyester, polyether, or polycaprolactone derived from an aliphatic or aromatic dicarboxylic acid, and an aliphatic or aromatic diol. 
     
     
       15. The apparatus of claim 1 wherein said cylindrical container comprises a closed head drum.